I would really like to use the Voigtländer 17.5 as an all-purpose lens on my E-M5, but it is too expensive and too large and heavy. So I ended using only AF mFT lenses, but in MF mode to a large degree.

Also played with some legacy OM lenses (50 f/1.4, 135 f/2.8, 200 f/4). But they do not offer anything over native mFT lenses.

My understanding is that a FF mirrorless system (such as Sony A7) is better suited for adapting legacy glass (when the corner softness / vigetting / colour shift issue is solved). I am dreaming of a small FF mirrorless body and adapted Leica M glass. Time will tell.